Numerical study of Ellis-micropolar tetra-hybrid nanofluid flow over a stretching surface with g-jitter and magnetic dipole

Abstract Improving thermal performance and stability in base fluids is a long-standing challenge, and one promising solution has been the use of hybrid nanoparticles to exploit their enhanced thermophysical and chemical properties. This study provides a detailed numerical exploration of unsteady magnetized tetra-hybrid nanofluid flow through a porous stretchable surface, integrating Ellis and micropolar rheological impacts. The model accounts for important factors, including magnetic dipole, nonlinear thermal radiation, viscous dissipation, cross-diffusion, Joule heating, time-dependent microgravity (g-jitter), thermophoresis, heat source/sink, and flow through porous media with variable transport features. Through the use of suitable non-dimensional variables, the original flow model is reduced into a set of non-dimensional partial differential equations. The resulting flow equations are solved using the overlapping grid-supported multi-domain bivariate spectral local linearization technique. Numerical results for various parameter values demonstrate how the flow system responds to different physical impacts. Simulations highlight that the combined effects of g-jitter and magnetic dipole forces play a crucial role in altering the boundary layer thickness and the dynamic stability of the fluid flow. The combined improvement of fluid temperature and associated heat transfer rate necessitates the inclusion of nonlinear radiation, variable thermal conductivity, and heat boundary conditions in the model. Species concentration enhances with activation energy, variable mass diffusivity, thermal-diffusion, and solutal boundary effects, though strong thermal-diffusion and activation energy reduce the rate of mass transportation. Yamada–Ota tetra-hybrid nanofluid model and lamina-shaped nanoparticles are characterized by superior heat transfer performance. The developed model has practical relevance in advanced thermal and fluid transport systems, including spacecraft cooling under g-jitter, energy systems involving porous media, and smart cooling systems where intricate multi-scale interactions and enhanced heat transfer using hybrid nanofluids are essential.